I'm travelling by an intercity train run by SJ from Arlanda C (i.e. Arlanda Central station), and as such I'll have to find my way to the train station there. Looking at Arlanda's page about taking the train1, long-distance trains arrive and depart from "Arlanda Central station in SkyCity". This, to me, would imply that this is a different station from Arlanda South and Arlanda North mentioned on the same page. However, looking at the map over SkyCity2, it looks like the entrances to Arlanda Central station and Arlanda North are located in the same place. However, looking at the map over terminal 5, only the express train station (i.e., Arlanda North) is mentioned.
With this in mind I would like to know, are these stations located in the same place? And, can I just walk to the entrance to Arlanda North in terminal 5 to get to the intercity trains, or do I have to first head to SkyCity and use that entrance?